Various types of soft tissue are normally attached to bone. By way of example but not limitation, ligaments connect bone to bone, and tendons connect muscle to bone. By way of further example but not limitation, the labrum is soft tissue which is connected to the rim of the acetabular cup (i.e., bone) so as to form a natural seal for the hip joint.
Such bone-connected soft tissues may become detached from their host bone as the result of injury and/or disease. By way of example but not limitation, a ligament or tendon or labrum may all be detached from bone due to a sports-related injury. A detached ligament or tendon can cause anatomical instability, impede proper motion of the joint and cause pain. A detached or damaged labrum can impede proper motion of the hip joint and cause pain in the hip. In all of these cases, as well as numerous others, the corrective treatment typically involves surgically re-attaching the soft tissue to bone.
In addition to the foregoing, in some cases it may be necessary to intentionally detach soft tissue from bone in order to provide a therapeutic treatment. In these situations it is generally necessary to thereafter re-attach the soft tissue to its host bone. By way of example but not limitation, where a patient suffers from a pincer-type femoroacetabular impingement (FAI) of the hip joint, it may be necessary to remove the overgrown portion of the acetabular rim in order to alleviate the pincer-type impingement. This generally involves surgically detaching the labrum from the acetabulum, debriding the underlying acetabular bone, and then re-attaching the labrum to the acetabulum.
Thus it will be seen that in many cases it may be necessary or desirable to attach (or re-attach) soft tissue to bone.
Historically, soft tissue has been attached (or re-attached) to bone using nails, screws, staples and suture extended through holes formed in the bone. All of these approaches suffered from a variety of deficiencies, including loosening, tissue necrosis, etc.
More recently, suture anchor assemblies have been used to secure soft tissue to bone. More particularly, these suture anchor assemblies generally have two suture strands attached to a suture anchor body, the suture anchor body is deployed in the bone, and then the suture strands are used to tie the soft tissue to the bone. This is done by passing one or more of the suture strands through the soft tissue, properly tensioning the suture, and then tying a knot (or knots) in the free ends of the suture so as to secure the soft tissue to the bone.
While such suture anchor assemblies have proven to be a major advance over earlier attachment techniques, they suffer from the serious disadvantage of requiring the surgeon to tie a knot (or knots) in the suture. More particularly, it can be time-consuming and technically challenging to form a tight knot in the suture, particularly during arthroscopic procedures where the soft tissue attachment needs to take place at a remote location within the interior of a joint. Such remote knot-tying is currently done by forming a suture throw outside the joint, sliding the suture throw down to the surgical site using a suture rundown tool, forming a second suture throw outside the joint, sliding that second suture throw down to the surgical site using the suture rundown tool, etc. until the knot is formed. It will be appreciated that, at best, this procedure is time-consuming and, at worst, results in a knot which may provide inadequate securement and/or improper tension to the soft tissue.
The present invention is intended to provide a novel suture anchor assembly which may be used to secure soft tissue to bone without requiring the surgeon to tie a knot (or knots) in the suture, and while permitting the surgeon to control the tension with which the soft tissue is secured to bone.